Self-templated hollow LiMn2O4 nanofibers as extremely long lifespan lithium ion battery cathode

Abstract

The poor cyclability and inferior capacity retention caused by severe Jahn–Teller effect and dissolution of Mn ions into electrolyte during cycling hinder the commercial application of spinel LiMn2O4 with low cost and non-toxic. Herein, hollow LiMn2O4 nanofibers composed of LiMn2O4 nanograins are proposed, forming 3D network framework with uniform distribution. The slender and firm nanofibers can effectively buffer the irreversible phase transitions triggered by Mn3+ disproportionation and Jahn–Teller distortion and lead to the extremely long cycle life of LiMn2O4 cathode. Meanwhile, the huge specific surface area provided by hollow structure ensures the full contact between the materials and electrolyte, being beneficial to the diffusion of Li ions and transfer of electron to maintain its capacity. It can be observed that the capacity retention is 97.5% after 1000 cycles at 1C. The structure design of the hollow nanofibers modified the LiMn2O4 cathode material at the micro-level, which greatly improves the long-term cycling stability of the material and provides reference for the modification in lithium ion batteries.